1: With methanesulfonyl chloride; triethylamine in dichloromethane T=5°C; 1 h; 2: With formic acid; potassium formiate; acetic anhydride T=70 - 95°C; 5 - 9 h;

in water; acetone T=45°C; 3 h;

1: With dimethyl sulfate in water; acetone T=45°C; 3 h; 2: With potassium hydrogencarbonate; triethylamine in water; acetone T=45°C; 1 h;

1: With methanesulfonyl chloride; triethylamine in dichloromethane T=0°C; 1.41667 h; 2: With formic acid; potassium formiate; acetic anhydride T=40 - 95°C; 2 h;

1.1: 77.7 percent / boron trifluoride diethyl etherate; EtOH; isopropanol / acetonitrile / 24 h / -18.4 °C 2.1: potassium acetate; dibromantin / acetone; H2O / -10 °C 3.1: aq. HCl / CH2Cl2 / 2.5 h / 20 °C 4.1: O3/O2 / CH2Cl2; propan-2-ol / 0.17 h / -55 °C 4.2: dimethylsilfide / CH2Cl2; propan-2-ol / 0.83 h / 20 °C 5.1: 0.865 mg / H2O2; KHCO3 / H2O; methanol / 16 h / 20 °C 6.1: 50.94 g / acetone; H2O / 3 h / 45 °C View Scheme

1.1: potassium acetate; dibromantin / acetone; H2O / -10 °C 2.1: aq. HCl / CH2Cl2 / 2.5 h / 20 °C 3.1: O3/O2 / CH2Cl2; propan-2-ol / 0.17 h / -55 °C 3.2: dimethylsilfide / CH2Cl2; propan-2-ol / 0.83 h / 20 °C 4.1: 0.865 mg / H2O2; KHCO3 / H2O; methanol / 16 h / 20 °C 5.1: 50.94 g / acetone; H2O / 3 h / 45 °C View Scheme

formic acid; potassium formiate; acetic anhydride T=70 - 105°C; 6.5 h;

1.1: aq. HCl / CH2Cl2 / 2.5 h / 20 °C 2.1: O3/O2 / CH2Cl2; propan-2-ol / 0.17 h / -55 °C 2.2: dimethylsilfide / CH2Cl2; propan-2-ol / 0.83 h / 20 °C 3.1: 0.865 mg / H2O2; KHCO3 / H2O; methanol / 16 h / 20 °C 4.1: 50.94 g / acetone; H2O / 3 h / 45 °C View Scheme

1: 1.40 g / aq. HCl / 0.33 h / 20 °C 2: O3/O2 / CH2Cl2 / -78 - 20 °C 3: H2O2; KHCO3 / H2O / 1.5 h / 20 °C 4: 50.94 g / acetone; H2O / 3 h / 45 °C View Scheme

1: O3/O2 / CH2Cl2 / -78 - 20 °C 2: H2O2; KHCO3 / H2O / 1.5 h / 20 °C 3: 50.94 g / acetone; H2O / 3 h / 45 °C View Scheme